Automated portable pet toilet

ABSTRACT

A portable electromechanical apparatus for easily and hygienically managing and disposing of pet wastes. The apparatus contains separate solid and liquid waste collectors and containers, located beneath a platform. A waste receiving member is provided upon the platform upon which a pet&#39;s solid waste is deposited. Electronic circuitry detects the presence of a pet and judges whether excretion has taken place, whereupon the waste receiving member, bearing the excrement, is moved off the platform and into a solid waste receptacle. A mechanism for automatically opening the solid waste receptacle is provided.

BACKGROUND OF THE INVENTION

1. Field of the Invention (Technical Field)

This invention relates to an automated portable pet toilet in which aclean, unused portion of a waste-receiving member is providedautomatically each time the pet steps off a platform after excretion.

2. Background Art

Pets provide companionship, which is recognized as being beneficial tothe well-being of single working people, the elderly living alone, andchildren. The company of a pet can also relieve fatigue in pet ownersdriving long distances. Pets are, of course, popular among peoplegenerally. In each case, there is a need for a lightweight, convenient,and attractive portable pet toilet that does not require daily cleaningand that does not emit odors. The present invention meets that need forall pets, especially dogs and cats, which can be trained to excrete in agiven location.

There are several devices in the existing art which replace the ordinarylitter box. U.S. Pat. No. 3,937,182, to Kamimura, entitled Pet Toilet,discloses a pet toilet in which liquid and solid wastes are collectedseparately by means of a manually operated filter belt that slides overa sloped tray into two receptacles: one for collecting liquid waste, andone for collecting solid waste. This device requires daily maintenance,as, in order to clean the litter after each use, the pet owner mustoperate the belt manually.

U.S. Pat. No. 4,846,104, to Pierson, entitled Automatic Cat Toilet,describes a cat toilet in which cat solid waste and cat urine-saturatedlitter mass is separated from surrounding cat litter by automaticrotation. The rotation also serves to blend unused litter with thelitter previously in contact with the saturated litter mass. Afterprocessing, the cat waste is stored in a disposable waste bag liner. Therotation mechanism must be activated manually in order to separate outthe cat waste. Since the litter is reused, the cat's paws come incontact with bacteria, as in standard litter boxes.

U.S. Pat. No. 3,734,057, to Lee, et al., entitled Pet Toilet, disclosesa system based on a mechanism providing predetermined delay time inresponse to detection of a pet, and an output signal provided byphotoelectric means, which activates the cleaning of waste by waterflushing.

U.S. Pat. No. 4,729,342 to Loctin, entitled Self Cleaning Pet Toilet,discloses a housing with walls which are automatically sprayed withwater, and a sensor, informed by a timer, which closes the door of thehousing after the pet leaves the toilet.

In both immediately preceding cases, the portability of the pet toiletdescribed is limited by the connection to a water source and drain, aswell as by the expensive necessity for special installation, which thenlimits the capacity of the drain. These occupy shared space in thebathroom.

SUMMARY OF THE INVENTION

The present invention is of a portable pet toilet, an automated pettoilet, and a method of using an automated pet toilet.

The portable pet toilet of the invention comprises a platform, a wastereceiving member movable across the platform, a solid waste receptaclebelow the platform, a motorized assembly for moving the waste receivingmember toward the solid waste receptacle, and a liquid waste receptacle.In the preferred embodiment, the waste receiving member is a sheet ofpaper, most preferably a rolled strip of paper with its free end movableacross the platform. The motorized assembly comprises a motor and atleast one driver for moving the waste receiving member. The driver maybe a belt and pulley, interlinking gears, a sheet-driving roller havinga frictional surface, or a roller mounted endless belt. The inventionpreferably further comprises a holding member for holding the wastereceiving member firmly against the driver. The holding member may be atorsion spring and at least one rotatable holding roller pressed againstthe waste receiving member by the spring or may be at least onerotatable holding roller connected by a gear train to the motor.Preferably, the portable pet toilet further comprises an activator (suchas a motor control circuit) for actuating the motorized assembly after apet has excreted, and a rotary solenoid for automatically opening a lidin the solid waste receptacle.

The automated pet toilet of the invention comprises a platform, adetector of the presence of a pet upon the platform, a sensor of whetherthe pet has deposited excreta upon the apparatus, and a conveyor of theexcreta to a receptacle. In the preferred embodiment, the platformaccommodates both solid excreta and liquid waste and the detector is aninfrared sensor attached to a signal device signalling when the petsteps upon the platform and when the pet steps off the platform. Thesensor is preferably a minimum resident timer detecting circuit,comprising a variable resistor and a pet departure detecting circuit.Alternatively, the sensor may be a judgment circuit. The conveyorpreferably comprises a movable waste receiving member mounted upon theplatform and a motor, comprising a timer setting motor drive circuit anda variable resistor, energized by the signal device signalling when thepet steps off the platform or a manually actuable energizing circuit.The receptacle is preferably covered by a movable cover operated by arotary solenoid having a timer setting motor drive circuit or a manuallyactuable energizing circuit.

The method of the invention of using an automated pet toilet comprisesproviding a platform, detecting the presence of a pet upon the platform,determining whether the pet has deposited excreta upon the toilet, andconveying the excreta to a receptacle. In the preferred embodiment, themethod accommodates both solid excreta and liquid waste on the platform,detecting the presence of a pet further comprises supplying a signalwhen the pet steps upon the platform and supplying a signal when the petsteps off the platform, and determining whether the pet has depositedexcreta further comprises providing a minimum resident timer detectingcircuit, a pet departure detecting circuit, or a judgment circuit.Conveying excreta further comprises providing a movable waste receivingmember upon the platform, providing a motor energized by supplying asignal when the pet steps off the platform, or providing a rotarysolenoid energized by supplying a signal when the pet steps off theplatform.

Accordingly, it is a primary object of the present invention to providea light weight and portable pet toilet.

Another object of the invention is the provision of a fully automatedpet toilet that separates and removes both solid and liquid waste.

Yet another object of the invention is the provision of variable timingmeans for adjusting operation intervals.

An advantage is that the present pet toilet collects waste in separatecovered receptacles.

Another advantage of the invention is that it operates without a watersupply.

Yet another advantage of the invention is provided by its ease ofmaintenance and cleaning.

Still another advantage of the invention is its provision for rapidreplacement of expended components.

The pet's paws are not in contact with used litter, so the advantage ofindoors hygiene is maintained, and the recurring presence of a cleanportion of the waste-receiving member gives a sanitary appearance to thepet toilet in any room.

Other objects, advantages, and novel features, and further scope ofapplicability of the present invention will be set forth in part in thedetailed description to follow, taken in conjunction with theaccompanying drawings, and in part will become apparent to those skilledin the art upon examination of the following, or may be learned bypractice of the invention. The objects and advantages of the inventionmay be realized and attained by means of the instrumentalities andcombinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and form a partof the specification, illustrate several embodiments of the presentinvention and, together with the description, serve to explain theprinciples of the invention. The drawings are only for the purpose ofillustrating a preferred embodiment of the invention and are not to beconstrued as limiting the invention.

FIG. 1 is a partially cut perspective view of the present invention;

FIG. 2 is a sectional side view taken along a line X-X' of FIG. 1;

FIG. 3 is a sectional view taken along a line a-a' of FIG. 2;

FIG. 4 is a sectional view taken along a line b-b' of FIG. 2;

FIG. 5 is a sectional view taken along a line c-c' of FIG. 2;

FIG. 6 is a partial perspective view of a transfer system of motordriving power;

FIG. 7 is a plan view of the automated toilet for a pet;

FIG. 8 is a partially cut perspective view of the pet toilet showing arolled sheet installed;

FIG. 9 is a plan view of the pet toilet showing a rolled sheetinstalled;

FIG. 10 is a block diagram illustration of the electronic circuit;

FIG. 11 is a circuit chart illustration of the electronic circuit;

FIG. 12 is a timing chart showing when a pet steps on the platform;

FIG. 13 is a timing chart showing when a pet steps off the platform;

FIG. 14 is a partial perspective view of the cutting rollers;

FIG. 15 is a diagrammatic sectional view of the cutting rollers;

FIG. 16 is a partial front view of a transfer system of motor drivingpower of the second embodiment;

FIG. 17 is a partial side view of a transfer system of motor drivingpower of the second embodiment;

FIG. 18 is a sectional side view of the third embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS (BEST MODES FOR CARRYING OUTTHE INVENTION)

As shown in FIGS. 1 and 2, toilet body 10 is a rectangular-shaped boxthe top portion of which is mostly open. Mounted on the top portion oftoilet body 10 is a rectangular-shaped platform 12, on which a petsteps, and which can be assembled and disassembled for maintenance.Platform 12 has slits 13 through which the pet's liquid waste 14 isallowed to fall. Below platform 12 and enclosed by toilet body 10 isempty space 11.

Located below platform 12, above empty space 11, is liquid wastecollecting tray 15. Liquid waste collecting tray 15 is removably mountedon toilet body 10 so that it can be removed, cleaned, and laterreassembled.

Liquid waste collecting tray 15 receives liquid waste 14 as liquid waste14 falls through slits 13 of platform 12. The liquid waste collectingtray 15 acts as a funnel, since it is slanted downward from one end 10atoward the other end 10b of toilet body 10, and from front wall 29 andback wall 21, toward a center outlet hole 15a. At the end of liquidwaste collecting tray 15, on the side 10a, is attached a rotatable guideroller 42 that revolves and conveys waste-receiving member 41 smoothlyonto platform 12. Collected liquid waste 14 falls down into liquid wastereceptacle 47 through opening 51, located on the upper face of liquidwaste receptacle 47 and adjacent to center outlet hole 15a (see FIG. 2).

In space 11, under liquid waste collecting tray 15, driving motor 16,having built-in gears, is attached to toilet body 10. Output axis 17 ofdriving motor 16 is coupled with pulley 18. Pulley 18 is linked withV-belt 19, in turn linked with pulley 20, which is fixed to a sheetdriving roller 28.

Sheet driving roller 28 is mounted on the toilet body 10, adjacent theend of platform 12, opposite end 10a and above receptacle 45, so thatsheet driving roller 28 can be assembled and disassembled. At the end ofsheet driving roller 28, shafts 25 and 26 are fixed on each side, asshown in FIG. 4. Shafts 25 and 26 are mounted to the depressedsupporting bearings 23a and 23b, mounted on the inner side of the backwall 21 and front wall 29 in order that sheet driving roller 28 canrevolve freely. The top portions of bearings 23a and 23b are opened in aV-shape so that sheet driving roller 28 can be removed from toilet body10 for cleaning.

As illustrated in FIGS. 4, 5, and 7, an inclined guide rail 22a leads tothe V-shaped opening of depressed supporting bearing 23a and is attachedto back wall 21. In the same way, guide rail 22b and bearing 23b areattached to front wall 29. Guide rails 22a and 22b enable sheet drivingroller 28 to easily glide along guide rails 22a,22b, when placing sheetdriving roller 28 back on toilet body 10.

Reference is made to FIGS. 2 and 4. Pulley 20 is coaxially fixed toshaft 26, located at one end of sheet driving roller 28a. V-belt 19 islinked to pulley 20. Sheet driving roller 28, powered by driving motor16, is rotated via pulley 18, V-belt 19, and pulley 20, coupledrespectively in order for sheet driving roller 28 to revolve and carryforward waste receiving member 41 to solid waste receptacle 48.

Around both ends of the section 28a and 28b of sheet driving roller 28,a preferred width of frictional material, such as rubber, is wound toconstruct frictional rollers 31a and 31b. Holding roller 36a, comprisedof frictional material of a certain width, is rotatably mounted abovefrictional roller 31a. Holding roller 36a may comprise various kinds ofmaterial, but is preferably made from rubber. As best shown in FIG. 6,holding roller 36a is supported rotatably by axis 33a, which is fixed onthe edge of arm 35. The other end of arm 35 is pivotably mounted on theupper part of back wall 21 by post 32. Pivotably operated arm 35 isnormally urged in a counterclockwise direction by torsion spring 37received about post 32 (see FIG. 6). Thus holding roller 36a providesdownward pressure upon the upper surface of frictional roller 31a.

The explanation of the structure of holding roller 36b, which is locatedon the opposite side of holding roller 36a, is omitted, as it is thesame as for holding roller 36a.

When driving motor 16 is energized, the driving power is transmittedrespectively to pulley 18, V-belt 19, and pulley 20, one after another,and consequently to pulley 20, fixed coaxially on shaft 26 of sheetdriving roller 28, causing sheet driving roller 28 to revolve. Due tothe revolving of sheet driving roller 28, the rotating movement offrictional roller 31a and frictional roller 31b (which are on both sidesof sheet driving roller 28) is transmitted to corresponding holdingrollers 36a and 36b (which are paired with frictional rollers 31a and31b, vertically facing one another). The external surfaces of theserollers are constantly touching each other by the pressure from spring37. Thus, vertically paired frictional roller 31a and holding roller36a, as well as frictional roller 31b and holding roller 36b, cause eachother to rotate by frictional force. Thus, when waste-receiving member41, held at both edges, is led between these sets of rollers,waste-receiving member 41 can be transferred from one side of toiletbody 10a to the other side 10b in the direction of arrow A, as shown inFIG. 2.

FIG. 8 shows the function of waste-receiving member 41 on which thewaste excreted from a pet is received and transferred to the solid wastereceptacle 48.

Reference is made to FIGS. 2 and 3. Preferably located in space 11,under platform 12 and liquid waste collecting tray 15, iswaste-receiving member 41, in the rolled state referred to as rolledsheet 40. On the inner face of front wall 29 and back wall 21, a pair ofdepressed supporting bearings 38a and 38b are fixed on each face to holda shaft 39, mounted into the core of "rolled sheet" 40, in order torotate freely and cause the setting of a new roll into the toilet body10. Waste-receiving member 41, which receives the waste, thus may be ledonto platform 12.

In addition, platform 12 and liquid waste collecting tray 15 can beremoved from toilet body 10 in order to set the "rolled sheet" 40 intothe space 11 in toilet body 10. Shaft 39 is set into the core of the"rolled sheet" 40, and both ends of the shaft are placed onto supportingbearings 38a and 38b, which can be seen in space 11. Moreover, theinstallation of rolled sheet 40 is not limited to one method. It can bedone in other ways, such as installing an access door that can be openand shut freely onto a side wall of 10a of toilet body 10.

Reference is now made to FIGS. 2 and 8. The initial part of this rolledsheet 40 is paid out onto platform 12 via rotatable guide roller 42,which is attached to the end section 10a of liquid waste collecting tray15. Thus, waste-receiving member 41 is paid out onto platform 12, fedfrom rolled sheet 40. Both edges of waste-receiving member 41 are thenheld between holding rollers 36a,36b and frictional rollers 31a,31b,located at both ends of sheet driving roller 28. Waste-receiving member41 is led into solid waste receptacle space 48. Thus, waste-receivingmember 41, which has been paid out onto platform 12, is pulled by theserollers, held at both edges, conveyed by sheet driving roller 28, andthen transferred to solid waste receptacle 48. Meshed net 77, preferablycomposed of rubber or other high-friction material, is wound around theexternal surface of sheet driving roller 28 and between frictionalroller 31a and frictional roller 31b, in order to transportwaste-receiving member 41 without slippage. Meshed net 77 has a moreimportant function of preventing waste-receiving member 41 from adheringto sheet driving roller 28; if waste receiving member 41 is made ofpaper or a similar material, it may stick to sheet driving roller 28when wetted by liquid waste 14.

In this embodiment, use of meshed net 77 is preferred, but theembodiment is not limited to this use. An equivalent member may becomposed of a single cord spirally wound around sheet driving roller 28in the same manner as screw threads or similar structures.

FIG. 9 shows V-shaped notches in waste-receiving member 41. V-shapednotches 82 can be cut into the waste receiving member 41 in any patternwhich allows liquid waste 14, deposited by the pet on platform 12, tofall immediately through to the liquid waste collecting tray 15. Thenotches 82 prevent overflow of excessive liquid waste on thewaste-receiving member 41, especially when waste-receiving member 41 ismade of paper or similar waterproof material. The notches 82 effectivelyprevent liquid waste from spreading over the paper, keeping both edgesof the paper dry, which is important in maintaining the strength of theedges, held by the rollers 36a, 36b, 31a, and 31b.

In addition, in this embodiment, use of V-shaped notches 82 ispreferred, but it is possible to use small holes or the like, as long asthey have the similar function of allowing liquid waste 14 to flowthrough to the liquid waste collecting tray 15 under platform 12.However, in this alternative design, there is a concern that part of thesolid waste might soil platform 12 through the openings of the holesfacing and touching platform 12. By using V-shaped notches 82, there isless likelihood of solid waste matter touching platform 12.

Additionally, if waste receiving member 41 is made of paper or similarlypermeable material, the following could be considered as a way ofkeeping the edges of the paper dry: the edges could be waxed or oiled toprevent weakening when wetted by liquid waste.

In the present embodiment frictional material is preferred for thefrictional roller 31, but it is not limited to such material. As long asthis member has frictional capability in its design, any substitute suchas a "rollette" design can be used instead of this frictional material.

Number 24 in FIG. 1 shows a window through which the amount ofwaste-receiving member 41 remaining on the rolled sheet 40 can be seenand the need for replacement of a new rolled sheet 40 can then bedetermined.

Referring to FIGS. 1 and 2, receptacle section 43 consists of an emptyspace portion 44, receptacle 45, and lid 46. Space 44 is located at side10b of toilet body 10. Receptacle 45 can be slidably inserted into andwithdrawn from this space 44 freely.

Receptacle 45, a rectangularly shaped box, is divided into two chambersby partition 49, defined as liquid waste receptacle 47 and solid wastereceptacle 48, and maintained in order to segregate the liquid wastefrom the solid waste, as the two wastes mixed would generate a strongodor. The top face of each receptacle 47,48 is open to take in thewaste. Lid 46 covers the opening of solid waste receptacle 48, thuspreventing escape of unpleasant odor. Lid 46 is attached to the freeside or edge of stage 53, which is fixed to the inner side of toiletbody 10, surrounded by back wall 21, another side wall 10b, and frontwall 29, all situated above solid waste receptacle 48, as best shown byFIGS. 2 and 7. Lid 46 is mounted between front wall 29 and back wall 21,adjacent stage 53 with rotary pivots 30a and 30b for opening andshutting the lid. Pivots 30a and 30b extend from the side corners of lid46 adjacent stage 53. Referring to FIG. 5, it is observed that pivot 30bis mounted pivotably and supported on a recessed bearing 27, which isfixed on the inside face of front wall 29. Pivot 30a is coupledrespectively with rotary solenoid 54, which is coaxially mounted at thecenter of the inner face of back wall 21, between stage 53 and lid 46.The driving axis 55 of rotary solenoid 54 is coupled with pivot 30a viacoupling 56, so that when rotary solenoid 54 is actuated axis 55 rotatescoupled pivot 30a. This rotary movement is then imparted to lid 46,causing it to rotate in a clockwise direction (as seen in FIG. 2).Consequently, lid 46 opens when rotary solenoid 54 is driven.

When electrical power is shut off, lid 46 is shut by a built-in springwithin rotary solenoid 54. In this embodiment, the use of rotarysolenoid 54 is preferable, but a plunger solenoid or other device couldbe used as long as such a mechanism serves the same function of openingand shutting lid 46.

When it becomes necessary to empty the waste from the receptacles 47,48the receptacles 47,48 are taken out from toilet body 10. Waste receivingmember 41, which is led in a continuous sheet from platform 12 to thesolid waste receptacle 48, has to be cut and separated transversely atthe end of sheet driving roller 28 in order to take receptacles 47,48out from the housing space 44. It could be cut by using an ordinarycutter along the free transverse edge of lid 46, or by a cutter fixed onthe end of lid 46 at the time lid 46 is shut.

As clearly illustrated in FIG. 2, an infrared sensor 57 is installed onthe upper part of the internal surface of side wall 10b to detect thepresence of the pet when it gets on or off platform 12. The outputterminal of infrared sensor 57 is connected with an input terminal ofelectronic circuit section 58. An output terminal of electronic circuitsection 58 is connected with an input terminal of driving motor 16.

The explanation of electronic circuit section 58 can be found in FIGS.10 and 11.

An output of the infrared sensor 57 is connected to the input of thesensor output detecting circuit 59 of electronic circuit 58. Sensoroutput detecting circuit 59 supplies an H-level signal when a pet stepson platform 12, and an L-level signal when the pet steps off platform12. The output of sensor output detecting circuit 59 is connected to theinput of the departure detecting circuit 60 (for the time at which thepet steps off) when a pet steps off platform 12. Departure detectingcircuit 60 is comprised of inverter 61, which is connected to the outputof the sensor output detecting circuit 59 and an input terminal of nandgate 64. The other input terminal of nand gate 64 is connected toinverter 61 via inverter 62 and integrating circuit 63. Inverter 65 isconnected to the output of nand gate 64.

Departure detecting circuit 60 supplies an H-level signal at the timewhen the pet steps off the platform 12.

The output of the departure detecting circuit 60 is connected with theT-input-terminal of judgment circuit 66, which is a Q-type flip-flopcircuit 66a.

The output of the sensor output detecting circuit 59 is also connectedwith the input of a minimum resident time detecting circuit 67 whichmeters the time considered normal for a pet to eliminate. Minimumresident time detecting circuit 67 comprises a non-trigger type one-shotmultivibrator 67a. It supplies an H-level signal at a preset time afterthe pet steps on platform 12. This required time means a duration oftime which is assumed to be from when the pet steps on the platformuntil the pet steps off the platform 12 for reasons other thanelimination of waste. In this embodiment, this required time is set upas 3.8 seconds. When the pet stays on platform 12 more than 3.8 seconds,minimum resident time detecting circuit 67 judges that the pet completedexcretory function. However, this time can be set according to any timeestimated as necessary for excretion.

This timer can be set for an optional time by adjusting the variableresistance of one-shot multivibrator 67a.

Output of the minimum resident time detecting circuit 67 is connected tothe D-input-terminal of judgment circuit 66. Therefore judgment circuit66 judges whether the pet remained on platform 12 the required time of3.8 seconds, by means of an output signal to the Q-terminal. The outputsignal to the Q-terminal is reversed from an input signal on theD-terminal at the time an H-level input signal is input to theT-input-terminal of judgment circuit 66. This means judgment circuit 66judges whether the pet finished excretory function by timing when thepet steps off platform 12. That is to say, judgment circuit 66 judgeswhether the pet stayed on platform 12 longer than 3.8 seconds.

The output of the sensor output detecting circuit 59 is also connectedto the input of time setting circuit 68 for driving the motor.

The time setting circuit 68 is comprised of a non-trigger type one-shotmultivibrator 68a, which supplies an H-level signal for a certainadjusted time at the moment a pet steps on and off platform 12.

In addition, the time set for driving motor 16 is the time required totransport the solid waste on waste receiving member 41 into the solidwaste receptacle 48. In this embodiment, it is set at approximately 15seconds. In addition, an optional value time can be set by adjusting thevariable resistance of the time setting circuit 68.

One of the output terminals Q of the time setting circuit 68 isconnected to one of the input terminals of gate circuit 69, whichconsists of nand gate 69a. The other output terminal Q of the timesetting circuit 68 is connected with the reset pulse transmittingcircuit 70. Reset pulse transmitting circuit 70 comprises nand gate 71,one of the input terminals of which is connected to a Q output terminalof time setting circuit 68, and also, via inverter 72, to integratingcircuit 73, which are disposed between another input terminal of nandgate 71 and Q output of motor driving time setting circuit 68. Resetpulse transmitting circuit 70 supplies an L-level output signal when anH-level signal from time setting circuit 68 changes to an L-levelsignal, at the time when the motor driving time is over. The output ofthe reset pulse transmitting circuit 70 is connected to the resetterminal of the judgment circuit 66.

Output terminal Q of the judgment circuit 66 is connected with an inputterminal of gate circuit 69. The output of gate circuit 69 is connectedto driving motor 16 through motor control circuit 74. The output of gatecircuit 69 is also connected to rotary solenoid 54 through a solenoiddriving circuit 75. Consequently, rotary solenoid 54 is actuated to openlid 46 when electricity is supplied by the output from the gate circuit69, that is to say, rotary solenoid 54 is opening continually while thedriving motor 16 is working.

In addition, 83 shows a manually actuated circuit which initiates theconveying of waste receiving member 41 to solid waste receptacle 48.This is to say, pushing switch 83a energizes solenoid driving circuit75, causing lid 46 to open, and causing motor control circuit 74 to beoperated simultaneously, thereby driving sheet driving roller 28,frictional rollers 31a,31b, and holding rollers 36a,36b.

Also shown is power-on reset circuit 76. An output terminal of power-onreset circuit 76 is connected to a set-terminal of judgment circuit 66.When electric power is supplied, power-on reset circuit 76 initiatesjudgment circuit 66 to reset to its original condition.

The functions of the electronic circuit will be explained, withreference to the timing chart shown in FIGS. 12 and 13. The firstexplanation, A, is of a working action of the electronic circuit when apet stepping on platform 12 and stepping off, has completed the processof eliminating excreta.

A. Electric power is supplied, energizing power-on reset circuit 76, andsetting judgment circuit 66 to an initial condition. When a pet steps onthe platform 12, infrared sensor 57 detects the presence of the pet. AnH-level detection signal is supplied from sensor output detectingcircuit 59. At the time when the pet steps off platform 12, the signalis changed to an L-level signal (shown in FIG. 12 A). Moreover, as soonas the pet steps on platform 12, an H-level signal is supplied for 3.8seconds from minimum resident time detecting circuit 67 (shown in FIG.12 G). When the pet steps off platform 12, a detection signal issupplied from the inverter 65 of the departure detecting circuit 60(FIG. 12F).

Approximately 3.8 seconds or more is normally deemed sufficient for thepet to finish elimination. A signal which detects the pet stepping offplatform 12 is supplied to the T-input terminal of the judgment circuit66.

The input for input terminal Q of the judgment circuit 66 is already anL-level signal (FIG. 12G), so the Q-output terminal of the judgmentcircuit 66 supplies an H-level signal (FIG. 12M).

When a pet steps off platform 12, the output of the sensor outputdetecting circuit 59 becomes L-level (FIG. 12A). This causes a motordriving signal of H-level to be supplied from the time setting circuit68 (FIG. 12H). Therefore, when the condition of two input signals to thegate circuit 69 is completed, a motor driving signal is supplied for 15seconds from the output terminal of the gate circuit 69 to the motorcontrol circuit 74. Consequently, the driving motor 16 is driven for 15seconds. By this action, the waste receiving member 41, which is held bythe frictional rollers 31a,31b and holding rollers 36a,36b, is conveyedinto the solid waste receptacle 48 with the solid waste on it.

In addition, at the time when an H-level output signal coming from aQ-output terminal of the time setting circuit 68 drops, a reset signalof L-level is supplied from the nand gate 71 of reset-pulse transmittingcircuit 72, and is supplied to the reset terminal of the judgmentcircuit 66. Then, the output terminal Q of the judgment circuit 66becomes H-level. By this means, the other input terminal of the gatecircuit 69 is opened. In this way, the gate circuit 69 becomes ready tocorrespond with the next signal.

B. The second explanation B concerns the working of the electroniccircuit when the pet steps on and off platform 12 temporarily, withoutintention of eliminating excreta.

It is again assumed, in this sequence, that 3.8 seconds is theapproximate time required for elimination, from when a pet steps on theplatform 12 to the time when the pet steps off.

The timing chart, which is shown in the FIG. 13, is almost the same asthe one in FIG. 12, except for the following point: an output signalfrom the minimum resident time detecting circuit 67 is at H-level when apet steps off platform 12, so a detailed explanation is omitted. When apet steps off platform 12, an output signal from the departure detectingcircuit 60 is supplied to the T-input terminal of a judgment circuit 66.If the pet steps off within 3.8 seconds, the input signal to the Q-inputterminal of the judgment circuit 66 is H-level (FIG. 13G). This is whyan L-level signal is supplied to the Q-output terminal of the judgmentcircuit 66 (FIG. 13M).

As a result, no condition of two input signals to gate circuit 69 forms,gate circuit 69 closes (FIG. 13N), and the driving motor 16 is notenergized. The waste receiving member 41 is not conveyed into the solidwaste receptacle 48.

On the other hand, in order to get ready for the next use, the judgmentcircuit 66 is reset by receiving a reset signal which is supplied fromthe reset-pulse transmitting circuit 70 (FIG. 13L).

This reset signal is supplied when the output signal from the timesetting circuit 68 has dropped. Therefore, the other side of the inputterminal of gate circuit 69 is opened. The gate circuit 69 assumes astate which can react with a following signal.

In summary, this pet toilet, which is comprised of systematic functions,embodies a system in which an infrared sensor 57 detects the presence ofthe pet on the platform 12. When a pet steps on and off, a judgmentcircuit 66, part of an electronic circuit 58, determines whether or nota pet has eliminated excreta on platform 12, based upon a predeterminedtime interval. In case a pet does eliminate, driving motor 16 is drivenfor 15 seconds, and rotary solenoid 54 is actuated to open lid 46 for 15seconds. Driving power from the driving motor 16 is transmitted onpulley 18, V belt 19, pulley 20, and a sheet carry roller 28, in thatorder. Consequently, frictional rollers 31a,31b and holding rollers36a,36b rotate in a clockwise and counterclockwise directionrespectively, as viewed in FIG. 6. Both sides of waste receiving member41's edges are held between both rollers, and pulled by these rollers,and then are conveyed for 15 seconds to the right side of the toiletbody 10, which is shown in FIG. 2. Therefore, the waste receiving member41 is transferred to the solid waste receptacle 48 with the solid wasteon it, and at the same time, a new part of the waste receiving member 41is paid out onto the platform 12, fed from the rolled sheet 40 ready forthe next use.

Lid 46 is closed when the driving power is turned off, the rotarysolenoid 54 returns by means of a return spring, which is built-in torotary solenoid 54.

The liquid waste 14, which is on the platform 12, falls through theslits 13 to the liquid waste collecting plate 15. Liquid waste 14 isgathered into hole 15a within the liquid waste collecting tray 15, andled to the liquid waste receptacle 47. The open top of the liquid wastereceptacle 47 is closed by the bottom of collecting tray 15. The opentop of solid waste receptacle 48 is closed by lid 46 and stage 53,insuring that no odor caused by the waste can escape from thereceptacles.

When the waste collects and fills up the receptacles, the wastereceiving member 41 has to be cut, so that the waste can be disposed of.Waste receiving member 41 can be cut with an ordinary razor cutter alongthe top edge of the lid 46 transversely.

The receptacles 45 are pulled out by holding the handle 52 from thehousing section 44. The waste can be disposed of in a suitable place,such as a domestic toilet. Afterwards, the cleaned receptacles 45 can beinserted back into the housing section 44.

In case the pet does not stay on platform 12 for a long enough time toeliminate waste, or if a pet steps on the platform without purpose, thedriving motor 16 and the rotary solenoid 54 are not driven. So the wastereceiving member 41 is not moved, nor is waste receiving member 41consumed uselessly.

In the preferred embodiment, an infrared sensor 57 is used as the meansfor detecting the presence of the pet on platform 12. Detection is notlimited to this means, however. A sensor such as a supersonic sensor, aphotosensor, a gravity sensor, and humidity sensor, and others wellknown in the art, can be used as long as those sensors have a detectingfunction.

Moreover, as a means of detection for the presence of the pet, othermeans such as a micro-switch and the like can be used instead of thesensor, as long as it can supply the signal to the detecting circuit 59of the electronic circuit 58, and as long as it has the same function.

Moreover, in this invention, concerning the material for the wastereceiving member 41, various kinds of material such as paper, rubber,plastic film, vinyl, cloth, and the like, can be used.

As a preferable embodiment for this invention, a paper sheet isrecommended, since it is a water-soluble material which can be disposedof easily into a domestic toilet.

In the preferred embodiment, waste receiving member 41, as described, isused as a means of receiving solid waste, but it is not limited to thisdevice. Alternatively, an endless belt can be used as a means ofcollecting solid waste into receptacle 48.

In the preferred embodiment, for waste receiving member 41, a V-shapednotched sheet is used, but it is not limited to this device. A sheetwhich does not have V-shaped notches can also be used, as long as thatsheet has the functions of permeability and strength. In addition, inthis embodiment, a pre-notched sheet if V-shaped notches 82 is used, butit is not limited to this method of perforation. Notches canautomatically be made while moving through the guide roller 42, forexample, by the following means: a pair of rollers which have cutters asshown in FIGS. 14 and 15 can be attached in lieu of guide roller 42.These cutters bite into each other. The cutting rollers 78,79 arerotated respectively by a required driving means in the direction of thearrow, which is shown in FIG. 15. The sheet is led between thoserollers, and after coming through the cutting rollers 78,79, the sheetappears perforated with V-shaped notches.

In the preferred embodiment, the platform 12 is designed with slits 13which allow for drainage of liquid waste, but it is not so limited. Alattice structure or the like can be used, provided it has sufficientstrength to support the weight of the pet, and is constructed ofmaterial which is resistant to breakage due to the pet's claws.According to this device, there is less possibility for the wastereceiving member 41 to be torn by the pet's claws.

In the preferred embodiment, a pulley 18, a pulley 20, and a V-belt areused as a transmission system transmitting the power of a driving motor16 to rotate sheet driving roller 28, but it is not so limited.Alternatively, a gear system, for example, can be used as a means oftransmitting the driving power.

In the preferred embodiment, a built-in geared driving motor 16 is used,but it is not limited to this method. For example, a step motor, whichis driven by a pulse operating from the motor driving control circuit74, which has the revolving speed controlled by it, and so on, can beused as a means for driving the sheet carry roller 28.

In the preferred embodiment, the time for minimum resident timedetecting circuit 67 is set for 3.8 seconds. It is not limited to this;the time can be adjusted to an optional value which is set inconsideration of the time when a pet steps off from the platform 12without excreting.

Time is set at 15 seconds for time setting circuit 68, but it is notlimited to this; it should be an optional value which is set inconsideration of the time required to convey waste receiving member 41,which received the waste on platform 12, to the solid waste receptacle48.

In the preferred embodiment, receptacle 45 is divided into twocompartments by partition 49, denoted a liquid waste receptacle 47 and asolid waste receptacle 48, but is not limited to this design. Thereceptacle for liquid waste and the receptacle for solid waste can existindependently of each other. Each receptacle can be taken out of thetoilet body 10 separately.

In addition, window 50 is provided on front wall 29 or side wall 10b,next to receptacles 47,48, in order to check whether the receptacles arefilled with waste.

Also, as an alternative, a disposable inner lining for the wastereceptacle can be available. This lining is made by disposable materialsand is formed corresponding to the dimensions of the waste receptaclebox and which contains the pet waste for simple removal.

The present invention is designed to connect to a source of directcurrent, since the rotary solenoid of the driving motor is run by directcurrent, such as a car battery or an ordinary battery. Alternatively,the invention could be connected to household current by use of acurrent rectifier.

Additionally, a hood which has one side open as an entrance and whichprovides shelter for the pet, could be provided to attach to the pettoilet as a cover.

In the preferred embodiment, sheet driving roller 28 and holding rollers36a,36b are vertically coupled in order to transfer the waste receivingmember 41 from the platform 12 to the receptacle 48 as a preferablemeans of facilitating the manufacture of a less costly and less complexproduct which has fewer maintenance problems. The main driving powerpulling the waste receiving member 41 is derived from two activefrictional rollers 31a,31b. The passive holding rollers 36a,36b functionto support the waste receiving member 41.

This embodiment, however, requires a more powerful mechanism to transfera greater amount of pet waste to the receptacle, because of theincreased weight of such pet waste. If the driving power of the holdingrollers 36a,36b were increased so that they rotate as do the frictionalrollers 31a,31b, then the waste receiving member 41 will be more able tomove a greater amount of pet waste to the receptacle 48.

The second, or alternative, embodiment describes this new function ofthe holding roller. The detailed description follows with reference toFIGS. 16 and 17.

On rotatably mounted axis 33, a holding roller 36a and upper gear 90 arefixed coaxially. The axis 33, mounted rotatably between upper part ofback wall 21 and supporting wall 94 in the through-hole bearing 95 whichis formed in an oval shape, is enabled to move up and down slightly.

Axis 33 is normally urged downwardly by spring 91. Below upper gear 90,tertiary gear 89 is fixed on shaft 26 so that upper gear 90 and tertiarygear 89 are respectively coupled. Shaft 26 is fixed by the center pointwith sheet driving roller 28, and mounted rotatably on the back wall 21,below the holding roller section. Between tertiary gear 89 and sheetdriving roller 28, inner gear 88 is fixed on shaft 26 coaxially so thattertiary gear 89, inner gear 88, and sheet driving roller 28 can berotated as a whole. Inner gear 88 and tertiary gear 89 are coupled withsecondary gear 87 and upper gear 90, respectively. Secondary gear 87meshes with primary gear 86. Primary gear 86 and gear 85 areconsequently coupled to the output axis 17 of driving motor 16.Therefore, when the driving motor is actuated, the driving power istransmitted to rotate upper gear 90 as well as tertiary gear 89 throughintegrally coupled output axis 17, broad gear 84, gear 85, primary gear86, and secondary gear 87. By this device, the driving power fortransporting the waste receiving member 41 is not only transmitted tothe frictional roller, but also to the holding roller, thus increasingthe pulling force.

Yet another alternate means of transferring the waste receiving memberto the receptacle is described as a third embodiment of the presentinvention with reference to FIG. 18.

By using an endless belt 96, constructed of some material such asnetting, the capacity for transferring a heavier amount of pet waste isobtained. Endless belt 96 is led around the sheet driving roller 28 andguide roller 42, and the upper part of the endless belt 96 is led ontothe platform 12. In this structure, the driving power for rotating thesheet driving roller 28, which is transmitted from the driving motor 16via pulley 18, V belt 19, pulley 20, respectively, causes the endlessbelt 96 to rotate in a clockwise direction continually.

Consequently, the "waste receiving member" 41 is transferred in thedirection indicated by arrow A to the receptacle 48, and continues overthe upper portion of the "liquid waste collecting tray" 15 and backthrough guide roller 42 to move across the platform 12 again. The newwaste receiving member is also paid out on the platform 12 due to thecontinuous movement of the endless belt 96. In the present embodiment,the waste receiving member is pulled by sheet driving roller 28 andslides across the platform 12 simply. However, in this third embodiment,the moving belt enables the pet toilet to accommodate a heavier amountof pet waste more effectively.

According to the present invention, a toilet for a pet can be automatedto detect, by metering time, whether the pet has eliminated or not, andhas a disposable arrangement for separating and covering the waste in areceptacle, comprised of the following parts: A toilet body (which hasreceptacles which retain the waste); a platform on which a pet canexcrete, (can be freely removed and replaced on the toilet body); awaste receiving member, which is led on the platform and receives thewaste on the part covering the platform; a transfer system which conveysthe waste receiving member across the platform to the receptacle; ameans of detection which detects when a pet has finished elimination andhas left the platform; a transfer control means which drives thetransfer system by an output signal from the detection means.

Therefore, the toilet body in this present invention can free the petowner from the constant concern of maintenance. It does not allow odorfrom pet waste to pervade the room since the waste is covered in thereceptacle. It provides a sanitary depository for pet excretion insidethe home. The waste receiving member on the platform is replaced with aclean waste receiving member at every instance of use and consequentlyhas neither offensive odor nor is unsightly until a convenient time forthe pet owner to restore cleanliness, for instance, after absence of afew days.

Although the invention has been described with reference to thesepreferred embodiments, other embodiments can achieve the same results.Variations and modifications of the present invention will be obvious tothose skilled in the art and it is intended to cover in the appendedclaims all such modifications and equivalents. The entire disclosures ofall applications, patents, and publications cited above are herebyincorporated by reference.

What is claimed is:
 1. A portable pet toilet comprising:a platform; areel; a strip of waste-receiving material rolled upon said reel andmovable across said platform; a solid waste receptacle below saidplatform; a free end of the strip disposable into said solid wastereceptacle; motorized means for moving said strip across said platformand into said solid waste receptacle; and a liquid waste receptacleseparate from the solid waste receptacle and located below the platformto collect liquid waste that passes through said platform.
 2. Theinvention of claim 1 wherein said waste receiving member comprises asheet of paper.
 3. The invention of claim 1 wherein said motorizedmoving means comprises motor means and at least one driving means formoving said waste receiving member.
 4. The invention of claim 3 whereinsaid driving means comprises a belt and pulley means.
 5. The inventionof claim 3 wherein said driving means comprises interlinking gear means.6. The invention of claim 3 wherein said driving means comprises atleast one sheet-driving roller.
 7. The invention of claim 6 wherein saidsheet-driving roller comprises a frictional surface.
 8. The invention ofclaim 3 wherein said driving means comprises a roller-mounted endlessbelt.
 9. The invention of claim 3 further comprising means for holdingsaid waste receiving member firmly against said driving means.
 10. Theinvention of claim 9 wherein said holding means comprises spring means.11. The invention of claim 10 wherein said spring means comprises atleast one rotatable holding roller pressed against said waste receivingmember by a torsion spring.
 12. The invention of claim 9 wherein saidholding means comprises gear means.
 13. The invention of claim 12wherein said gear means comprises at least one rotatable holding rollerconnected by a gear train to said motor.
 14. The invention of claim 1further comprising means for actuating said motorized moving means aftera pet has excreted, said actuating means comprising:means for detectingthe presence of a pet upon said platform; and means for determiningwhether the pet has deposited excreta upon said strip of waste-receivingmaterial.
 15. The invention of claim 14 wherein said detecting meanscomprises an infrared sensor.
 16. The invention of claim 14 wherein saiddetecting means further comprises means for supplying a signal when thepet steps upon said platform and means for supplying a signal when thepet steps of the platform.
 17. The invention of claim 14 wherein saiddetermining means further comprises a circuit for detecting thedeparture of the pet from said platform.
 18. The invention of claim 14wherein said determining means further comprises a circuit for detectingminimum resident time.
 19. The invention of claim 18 wherein saidcircuit for detecting minimum resident time comprises a variableresistor.
 20. The invention of claim 14 wherein said determining meansfurther comprises a judgment circuit.
 21. The invention of claim 16wherein said motorized moving means comprises a motor actuated by saidmeans for supplying a signal when the pet steps off said platform. 22.The invention of claim 14 wherein said motorized moving means furthercomprises time setting motor drive circuit means.
 23. The invention ofclaim 22 wherein said time setting motor drive circuit means furthercomprises a variable resistor.
 24. The invention of claim 14 furthercomprising:movable lid upon said solid waste receptacle; and means forautomatically opening said lid.
 25. The invention of claim 24 whereinsaid automatic opening means comprises a rotary solenoid.
 26. Theinvention of claim 25 wherein said rotary solenoid further comprisestime setting motor drive circuit means.
 27. The invention of claim 7wherein said frictional surface comprises a net covered surface.
 28. Theinvention of claim 2 wherein said sheet of paper comprises a perforatedsheet of paper.